Microplasmas

Microwave plasma sources are particularly interesting for two fields of application: On the one hand for low-pressure plasma technology, which is used in a wide variety of industrial applications and requires continuous improvements in terms of quality and efficiency - at ever lower costs at the same time. On the other hand, for atmospheric microplasmas, since they open up new plasma applications as well as allow low-pressure applications to be transferred to the much more cost-effective atmospheric processes.

  • [Atmospheric pressure microwave plasma source with air cooling
    [+] Atmospheric pressure microwave plasma source equipped with air cooling
  • Laboratory set-up of an atmospheric pressure microwave plasma source
    [+] Laboratory set-up of an atmospheric pressure microwave plasma source
  • Application example: plastic surface activated by plasma
    [+] Application example: plastic surface activated by plasma and spray-coated with water (left: after activation, right: before)

Microwave plasmas are characterized by a low plasma temperature, excellent plasma intensity and increased plasma homogeneity. They are generated by high-frequency electromagnetic fields, preferably those in the 2.45 GHz ISM band. However, the application of microwave frequencies required for this is limited in terms of plasma technology: The currently used magnetron sources are only available starting from a power of approx. 300 W, and the transmission of microwave energy from the generator to the plasma is very problematic. Therefore, integrated semiconductor-based systems consisting of generator and plasma excitation structure are required. These must operate reliably and be easy integrable into the applications at low cost. In particular, the high potential of efficient, high-density atmospheric microwave plasmas can only be exploited if extremely compact, integrated plasma sources are available. The FBH offers the suitable customized solutions.

Main focuses

  • Source design: Investigation and evaluation of different approaches for plasma sources and the associated microwave power oscillators.
  • Applications for atmospheric and low-pressure plasma sources, e.g. for efficient and cost-effective activation of surfaces in preparation for coating, printing, painting or bonding.